I think the Americans did their best against the overwhelming odds. The use of the CoC dice was a tiny bit "gamey" for me (or it would have been more so if it had worked) but it's in the rules I guess, the way it played out with the bazooka team getting caught in the open was completely reasonable though.
I understand how it can be seen that way. The ‘turn end’ is seen as one of those pauses in the action that occur, often for no obvious reason. I saw it as the Americans waiting patiently for the right moment, sensing a lull in the action and a chance to catch the Germans off their guard. A CoC die is a valuable thing and could have had several other uses, so I consider their use part of the tactical thinking of the platoon lieutenant. Someone on the lookout for the best opportunity to act.
In terms of the game’s narrative, the Germans have yet to spot any Americans, they may well have paused for a moment to consider what is happening or confer. I see use of the CoC die as the American commander seeing this happen, seizing the moment and telling the bazooka team that now is the time to surprise the Panther. Similarly the German use of the same is their commander being more alert to the situation than his men and making a rapid response to the ambush. I think it makes a plausible narrative. A CoC die is a valuable thing, to be used as an additional tactical asset, deciding when and how it can improve you performance is a key decision in the game.